Portable gas supply systems, also called portable pneumatic power sources, are used for powering pneumatic equipment, e.g., nailers, screwdrivers, hammer-drills, impact wrenches, etc., at construction sites and other locations where electricity is not readily available to power a conventional electric air compressor. Three types of conventional portable pneumatic power sources are known: gasoline or diesel engine-powered compressors; room-temperature storage systems having a single high-pressure tank holding compressed gas or fluid; and cryogenic-temperature storage systems having an insulated tank holding liquified cryogenic fluids. Each of these conventional types of power source has numerous disadvantages.
The disadvantages of conventional engine-powered compressors include: they are relatively expensive to purchase because of their mechanical complexity; they need frequent maintenance because of their large number of moving parts; their flammable fuel may constitute a fire hazard; their exhaust fumes are hot and may be toxic if operated in a confined space.
The disadvantages of conventional room-temperature storage systems include: the heavy storage tank typically used in such systems may be difficult to move around the site, especially onto elevated floors or scaffolding.
The disadvantages of conventional cryogenic-temperature storage systems include: the cryogenic fluid must be obtained from specialized suppliers, and may not be available in all areas; and the cryogenic fluid cannot be stored indefinitely when not being used, but instead will “boil off” over time (as waste).
A need therefore exists for an improved pneumatic power supply for pneumatic equipment that overcomes these shortcomings of the prior art and/or provides additional features not present in the prior art.